(a) Field of the Invention
The present invention relates to a laser welding device for a roll forming system and a control method thereof. More particularly, the present invention relates to a laser welding device for a roll forming system and a control method thereof which is disposed at the rear of a roll forming unit and laser welds each welding position of a shaped beam in real time by controlling an output and a moving speed of a focus of a laser beam according to a forming speed.
(b) Description of the Related Art
Generally, a roll forming method is a method in which a coil is uncoiled and the coil is bent to various shapes by passing through a roll forming unit including a plurality of roll formers respectively provided with an upper forming roll and a lower forming roll. The roll forming method is used for manufacturing beams of linear type (particularly, a bumper beam for a vehicle) which is bent to the various shapes.
FIG. 1 is a schematic diagram of a roll forming system according to a conventional art which performs a roll forming method.
As shown in FIG. 1, the roll forming system according to the conventional art includes an uncoiler 201 at a front portion of a process line, and the uncoiler 201 performs an uncoil step S110 at which a coil 200 is uncoiled. A straightener 203 is provided at the rear of the uncoiler 201 and performs a straightening step S120 at which the coil uncoiled from the uncoiler 201 is straightened to a panel 250 of plate shape.
In addition, a brake press 205 is disposed at the rear of the straightener 203 and performs a piercing step S130 at which a plurality of holes for assembling is formed at the panel 250 supplied from the straightener 203.
In addition, a roll forming unit 207 including at least seven roll formers R1-R7 is disposed at the rear of the brake press 205 and performs a roll forming step S140 at which the panel 250 passing through the uncoiler 201, the straightener 203, and the brake press 205 is sequentially bent such that a shaped beam 260 is formed.
In addition, a round bender 209 for forming the shaped beam 260 to have a predetermined curvature is disposed at the rear of the roll forming unit 207. The round bender 209 is provided with a shaped surface having the predetermined curvature and performs a bending step S150 at which the shaped beam 260 passes through the shaped surface so as to be manufactured as the shaped beam 260 having the predetermined curvature.
In addition, a cutting press 211 for cutting the shaped beam 260 in a predetermined size is disposed at the rear of the round bender 209 and performs a cutting step S160 at which the shaped beam 260 is cut in a size of the finished product.
A bumper beam 300 for a vehicle bent to have a closed section, as shown in FIG. 2, is manufactured through the roll forming system.
However, in a case of the bumper beam 300, both ends of the closed section should be welded through a spot welding (SW) or a cold metal transfer (CMT) welding at an additional welding process.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.